Useful feature IMHO. I only did one test run using an 8 minute Bruch violin CD track (so 40 minutes total test time), where I listed to each track just once before ranking. Clearly I should do more test runs with different recordings on different audio systems. The test was run on my desktop using the motherboard Realtek audio chip and Pioneer BR41 speakers, alternative options are to replace the Realtek with an ODAC USB DAC, and also run tests on my more expensive (higher quality?) home theater audio system to see if I can repeatedly, accurately discern differences in all three equipment sets, just the more expensive system or none at all.
In my one run through, my 58 year old ears detected the the 32k and 64k accurately but didn't rank the 128k, 256k and Flac correctly. For reference, I have no history of exposing my ears to loud concert music but online audio tests played back through the first set of equipment suggest a high end frequency limit of ~13-14k. I deliberately chose a relatively long audio test segment to help reduce/avoid audio memory since it seems to me the value in a test like this is to see what one perceives in absolute terms without a relatively recent audio reference to compare to. Comparing relatively short audio snippets may enable me to be more accurate at the higher bit-rates but its not how I listen to (and enjoy) music.
Interestingly my perception of 128k classical audio streams has been that they sound "compressed" and "lacking highs" when selecting either higher bit rate streams or playing back my CD rips, but there are so many other differences when doing so that its actually meaningless, so I'll be interested in more rigorously testing the ability to determine between 128k vs 256/Flac .
